Fibromyalgia (new lat., fibro- fibrous tissue, Gk. myo- muscle, Gk. algos- pain), meaning muscle and connective tissue pain (also referred to as FM or FMS), is a disorder classified by the presence of chronic widespread pain and a heightened and painful response to gentle touch (tactile allodynia). Other core features of the disorder include debilitating fatigue, sleep disturbance, and joint stiffness. In addition, persons affected by the disorder frequently experience a range of other symptoms that involve multiple body systems, including difficulty with swallowing, functional bowel and bladder abnormalities, difficulty breathing, diffuse sensations of numbness and tingling (non-dermatomal paresthesia), abnormal motor activity (i.e. nocturnal myoclonus, sleep bruxism), and cognitive dysfunction. An increased prevalence of affective and anxiety-related symptoms is also well known. While the criteria for such an entity have not yet been thoroughly developed, the recognition that fibromyalgia involves more than just pain has led to the frequent use of the term "fibromyalgia syndrome". Not all affected persons experience all the symptoms associated with the greater syndrome.

Fibromyalgia is considered a controversial diagnosis, with some authors contending that the disorder is a ‘non-disease', due in part to a lack of objective laboratory tests or medical imaging studies to confirm the diagnosis. While historically considered either a musculoskeletal disease or neuropsychiatric condition, evidence from research conducted in the last three decades has revealed abnormalities within the central nervous system affecting brain regions that may be linked both to clinical symptoms and research phenomena. Although there is as yet no generally accepted cure for fibromyalgia, there are treatments that have been demonstrated by controlled clinical trials to be effective in reducing symptoms, including medications, patient education, exercise, and behavioral interventions.

Signs and symptoms

Common signs and symptoms of fibromyalgia.

The defining symptoms of fibromyalgia are chronic, widespread pain and painful response to touch (allodynia). Other symptoms can include moderate to severe fatigue, needle-like tingling of the skin, muscle aches, prolonged muscle spasms, weakness in the limbs, nerve pain, functional bowel disturbances, and chronic sleep disturbances. Sleep disturbances may be related to a phenomenon called alpha-delta sleep, a condition in which deep sleep (associated with delta waves) is frequently interrupted by bursts of alpha waves, which normally occur during wakefulness. Slow-wave sleep is often dramatically reduced.Fact: date=May 2008